Distance of pv panels from roof?

[Canine]

I have a slide in camper and want to keep height as low as possible, but don't want to turn my camper into an oven by mounting panels directly against the roof. What would be a minimal gap from the roof when the panels need to lie flat? What would be the ideal gap if height weren't an issue? The overall height of the camper without panels is about 10 feet or a little over 3 meters.

 

[Willy]

I used 1" square aluminum tube to mount my panels on the camper I had. I'd also have the polycrystalline panels situated over my roof vent (with the cap taken off), which had my solar extractor fan blowing through it. This would cool the panels/roof. The Unisolars, heat loving aw they are, weren't cooled, though I'd have then at a bit of an angle. ..Willy.

 

[Canine]

Willy, were you satisfied with a 1 inch gap or would you have preferred more?

 

[Willy]

With the fan blowing underneath I was satisfied. Also, my roof is painted white (NOT silver), which makes a HUGE difference. With my current setup, the Grumman step van, I don't have any roof vents and, with the same 1" spacing, I notice that it's a bit warmer on the ceiling inside directly under my panels. It's not enuf to get me tearing my hair out tho.

I don't want to have the panels any higher for 3 reasons: added wind resistance, possibility of getting torn off by a low hanging limb, and slightly higher centre of gravity. I'll admit that we're talkin' incremental differences with the 1st & last, but it all adds up in the end. ..Willy.